RUSTSEC-2026-0307 `uncbv`: archive extraction is vulnerable to path traversal (zip-slip)
A malicious archive can write files outside the intended directory via path traversal, requiring user interaction to extract the file.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is RUSTSEC-2026-0307?
RUSTSEC-2026-0307 is a path traversal vulnerability in uncbv, published on 23 Sep 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
Summary
uncbv extract writes each archive entry to output_dir.join(entry_filename) using the filename stored in the archive with no check for .. components or absolute paths. A malicious .cbv / .cbz archive whose entry name contains ../ (or an absolute path) can therefore cause files to be written outside the output directory chosen by the user. This is a "zip-slip" / directory-traversal arbitrary file write (CWE-22).
Which versions are affected by RUSTSEC-2026-0307?
1 open source package ship an affected version, including uncbv.
| Package | Affected | Fixed in |
|---|---|---|
uncbv crates.io | From 0.0.0-0 | 0.3.1 |
How do I fix RUSTSEC-2026-0307?
Upgrade uncbv to 0.3.1 or later.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is RUSTSEC-2026-0307 being exploited?
There is no known exploitation of RUSTSEC-2026-0307 in the wild and no public exploit code.